This proposal is a request for an NIMH Child and Adolescent Mental Health Academic Award which would allow for the development of the P.I. as researcher and as a resource for the Child and Adolescent Psychiatry Division at Hahnemann University. The research plan involves an efficacy study of lithium for the treatment of aggressive conduct disorder and developing a research clinic for developmental disabilities. Aggression in children is a major public health concern, and lithium shows promise in being a treatment for conduct disorder characterized by aggressive behavior, but its efficacy has not been established. The proposed study would be a 6 week double-blind placebo controlled study of lithium (serum level, 0.8 to 1.2 mEq/L) in aggressive conduct disordered children, aged 10 to 17 years, who are inpatients. Aggressive acts will be measured on the Overt Aggression Scale. This study will compensate for the methodological deficits in previous studies. Some studies employed only global measures of aggression, while others utilized an inadequate time period for the lithium trial. This study will employ a specific measure of aggressive acts and an adequate lithium trial period. The P.I. has developed a significant working relationship with two mentors, Magda Campbell, M.D., and George M. Simpson, M.D., both of whom are committed to acting as consultants for this research.